Module 3 Flashcards
What are some aspects on history that help determine between primary vs secondary haemostasis disorders?
PRIMARY
- immediate bleeding with cuts
- petechiae
- small/superficial ecchymoses
- epistaxis
- GI blood loss
- menorrhagia
SECONDARY
- haemarthrosis, muscle bleeds
- large, deep ecchymoses
- delayed bleeding
- internal bleeding
What is the bleeding assessment tool used for?
What are the ranges for normal?
Differentiates normal vs abnormal bleeding
Normal range is
<4 in adult males
<6 in adult females
<3 in children
List some bleeding disorders that are
- X linked recessive
- autosomal dominant
- autosomal recessive
XL
- haemophilia A
- haemophilia B
AD
- vWD type 1 and 2
- mild PFD
AR
- factor deficiencies
- rare severe PFDs
What are some causes of isolated APTT or isolated PT prolongation?
APTT Spurious Anticoagulants (heparin/dabigatran) Lupus anticoagulant vWD Haemophilia XI deficiency Clotting factor inhibitors
PT Warfarin Vit K deficiency Liver disease Rivaroxaban FVII deficiency or inhibitor
What is the dosing for factor VIII and factor IX concnetrates for perioperative replacement?
VIII
- twice daily bolus for standard half life
- 2% increment per unit per kg
IX
- once daily bolus for standard half life
- ~1% increment per unit per kg
can run continuous replacement for life-threatening bleed or major surgery
What are the factor level goals and duration for replacement in haemophilia for
- clinically significant bleeds
- major or life-threatening bleeds
- major surgery
Clinically significant
- 60-80% for 1-3 days
Major or life-threatening bleeds/major surgery
- 80-100% for 7-14 days
What is the role of desmopressin in perioperative vWD management?
- can release vWF stored in endothelial cells
- IV/SC/IN
- useful in type I, not at all useful in type III or 2B
Under what circumstances does vWF need to be loaded?
major surgery or haemorrhage
What are the target plasma of vWF levels for
- major surgery or haemorrhage
- minor surgery of haemorrhage
How long should they be maintained
MAJOR
- target >50U/dL
- maintain for 7-10 days
MINOR
- target>30U/dL
- maintain for 2-4 days
What are the diagnostic tests useful in platelet disorders?
Flow cytometry: assess size
Light transmission aggregometry to assess aggregation
Genetic studies
Electron microscopy to examine granules
What is the syndrome of thrombocytopenia in the presence of auditory or renal dysfunction?
MYH9- related thrombocytopenia
Describe the associated changes with GLANZMANNS thrombaesthenia
- defective product
- pattern of inheritance
- platelet count and morphology
- aggregometry characteristics
-platelet fibrinogen receptor, integrin αIIbβ3.
- Autosomal recessive
- Normal platelet count and morphology
- Normal coagulation assays
- No aggregation with all agonists except ristocetin but saw-tooth pattern
What is a platelet disorder that has normal platelet counts, and normal platelet aggregation?
Scott syndrome
Describe the associated changes with BERNARD SOULIER SYNDROME
- defective product
- pattern of inheritance
- platelet count and morphology
- aggregomeetry characteristics
What differentiates it from Mediterranean Macrothrombocytopenia, and Velocardiofacial [DiGeorge] Syndrome?
- GPIb/IX/V
- autosomal recessive
- thrombocytopenia GIANT platelets
- lack of response to ristocetin
ADMM: GP1balpha subunit fucked
VCDS: GP1bbeta subunit fucked
What is the treatment of choice for uraemic platelet dysfunction and why?
DDAVP
May provide some benefit in selected individuals with other platelet disorders and mild to moderate bleeds. Causes the release of VWF and factor VIII from endothelial cells and thereby increasing platelet adhesion.
